1. Field of the Invention
This invention belongs to the field of synthetic organic chemistry and provides a process for preparing acetyl-tertiary-alkanes. The compounds are particularly useful as intermediates for preparing a group of 3-alkylpyridazin-6-ylbenzamides which have recently been identified as valuable herbicides. The acetyl-t-alkanes have been difficult to prepare, because of the bulk of the tertiary alkyl group attached to the carbonyl, and the present invention provides a convenient synthesis of these intermediates.
2. State of the Art
Various processes have been used in the art to make acetylalkanes. Corey and Durst, J. Am. Chem. Soc. 90, 5548-52 (1968) made acetylcyclohexane and pinacolone by reacting the appropriate ethyl ester with lithium N-(p-tolyl)lithiomethanesulfinamide. House and Larson, J. Org. Chem. 33, 61-65 (1968), made acetylheptadecane by reacting the corresponding methyl ester with dimethylsulfone and sodium hydride to obtain the methylsulfonylacetyl intermediate, and reducing off the methylsulfonyl with aluminum amalgam. Phenylacetone, a related compound, was prepared by Oishi et al., Chem. Pharm. Bull. 17, 2314-18 (1969), by reacting ethyl phenylacetate with 1-ethoxy-N,N-dimethylvinylamine, deaminating the product on silica gel, and hydrolyzing in hot dilute acid.